Ragweed is one of the primary causes of seasonal allergies in the United States. This fact sheet provides general information about ragweed allergy. We hope that this material helps you better understand how to recognize ragweed allergy and know what to do about ragweed allergy if it affects you or someone in your family.

Please keep in mind that this information is not meant to take the place of medical advice from your own physician.

When five-year-old Travis started kindergarten in early Fall, he seemed to get a lot of colds and upper respiratory infections. His mother figured that since he hadn’t been in day care, his body was simply adjusting to the new germs he was exposed to by being with lots of other kids. But when Travis started wheezing and coughing all the time, the pediatrician suggested an allergy might be the cause. Allergy testing confirmed that Travis had developed sensitivity to ragweed pollen, which appeared at high levels in his town every September. With proper medicines and simple avoidance measures, his health improved significantly.

What is ragweed?

Ragweeds are soft-stemmed weeds that grow in much of the United States. They are tough and hardy, able to thrive in many places especially where soil disturbance occurs. Seventeen species, or more, of ragweed grow in North America. Ragweed belongs to a larger family of plants called Compositae. Other plants of this family include:

• Sage

• Burweed march elder

• Rabbit brush (bur ragweed)

• Mugworts, groundsel bush

• Goldenrods, marigolds, zinnias, sunflowers

Ragweed plants are most common in the east and midwest of the United States. Common ragweeds only live for one season, but each plant alone produces up to one billion pollen grains. After midsummer, as nights start to get longer, the ragweed flowers mature and release their pollen. Warmth, lowered humidity, and active breezes after sunrise help create the ideal environment for ragweed flowers to release pollen. The pollen then must travel by air to other ragweed plants to complete the fertilization process, resulting in seeds and more plants in the coming year(s).

Ragweed plants usually grow in rural areas as well as in urban waste places. Near the plants, pollen levels are highest shortly after dawn. The amount of airborne pollen peaks in many urban areas between 10:00 a.m. and 3:00 p.m., depending on the weather. Rain and/or low morning temperatures (below 50° Fahrenheit) can block or slow pollen release on that day.

Did you know . . . Ragweed pollen travels far! It has been measured in the air 400 miles out to sea and two miles up in the atmosphere. However, most ragweed pollen grains fall out fairly near their sources.

Ragweed plants are easily overgrown by various turf grasses and other perennial plants that come up from established stems every year. Ragweed also grows where the soil is disturbed by streams of water, cultivation, or chemicals (such as winter salting of roads). These weed plants are often found along roadsides and riverbanks, in vacant lots, and fields. Ragweed seeds can survive many decades in the soil, growing again when conditions become favorable.

What is ragweed allergy?

An allergy is the overreaction of the immune system to an allergen (usually a harmless substance). A person can come into contact with allergens by breathing; eating or drinking; touching; or having them injected into his or her body. Some people’s immune systems become changed so as to specifically react with these common substances. This is called “sensitivity.” Subsequent exposure to the substance(s) can trigger an allergic reaction.

People can develop an allergy to the pollen of ragweed plants. Ragweed induced nasal symptoms are often referred to as ragweed “hay fever.” When people who are allergic to ragweed inhale the pollen (allergens) circulating in the air, they develop the common symptoms of hay fever.

Who gets ragweed allergy?

People with allergies to one type of plant pollen (or to dust, animals, and/or fungi) tend to develop allergies to other pollens as well. Approximately 10-20 percent of Americans suffer from ragweed allergy. Family members with nasal allergy, asthma, or eczema are often reported.

People with an allergy to ragweed also may have similar symptoms when they eat cantaloupe and bananas— usually mouth itching. Sunflower seeds, chamomile tea, or honey containing pollen from Compositae plant family members occasionally can cause severe reactions, including shock.

What are the symptoms of ragweed allergy?

The allergic response to all plant pollens producing seasonal symptoms is commonly known as hay fever. The medical term for hay fever is “seasonal allergic rhinitis.” Symptoms of ragweed allergy include the following:

To identify an allergy to ragweed or one of its relatives, your physician will ask you about your medical history, especially the timing of your symptoms, and examine you. The main approach to confirm a suspected allergy is skin sensitivity testing.

With skin testing, your skin is gently scratched or pricked with a refined extract of ragweed pollen. In sensitive people, the site will turn red, swollen, and itchy. Sometimes blood tests are used to see if an antibody to ragweed is present. Blood tests may be necessary if skin testing is impractical, but they take longer for processing, are more expensive to perform, and more subject to error.

What is the treatment for ragweed allergy?

There is no cure for ragweed allergy but many ways to reduce discomfort. The best way to manage an allergy to ragweed is to avoid or minimize your contact with ragweed pollen during ragweed season.

Keep in mind . . . Ragweed pollen can be detected as early as mid to late July in certain areas. Most ragweed blooms in mid-August, with pollen levels peaking around early September. Ragweed season ends with the first hard frost, but levels are often low for weeks before.

Here are some ways to cut down on your exposure to the ragweed pollen.

• Track the pollen “count” for your area. The news media often report the pollen levels, especially when high. Check your local newspaper or call the weather information telephone number for your area.

Where to find the pollen count . . . The National Allergy BureauTM (NABTM) is the section of the American Academy of Allergy, Asthma, and Immunology’s (AAAAI) Aeroallergen Network that is responsible for reporting current pollen levels to physicians and the public. http://www.aaaai.org/nab/index.cfm?p=default

• Emphasize activities in centrally air-conditioned spaces. Window units set on “recirculate” or “vent closed” also can help. Various filter units and devices producing ultraviolet (UV) light and ions have unproven value.

• Keep the pollen off! Keep windows closed so the pollen cannot easily enter your house or car. Use dryers instead of outside line drying for laundry. Remove outer clothing before entering the house if you’ve been working or playing outside during the pollen season. Take a shower after being outside to remove pollen that collects on your hair and skin.

• Stay indoors. Airborne pollen tends to peak between the hours of 10:00 a.m. and 4:00 p.m. Try to take care of outdoor activity when the pollen levels are not at their peak.

• Get away from high pollen levels. People living in the eastern and midwestern United States—where ragweed thrives—may get significant relief by going west to the Rocky Mountains and beyond during the peak ragweed season. Traveling abroad in late summer also can greatly reduce your exposure. Be sure to check the areas where you might travel to make sure ragweed is not a problem there as well (parts of central/eastern Europe have a late summer ragweed season.)

Should you make a permanent move? People with severe nasal allergy and asthma symptoms due to ragweed may consider living in a place with less ragweed. Generally the west coast of the U.S. offers the lowest exposures. Although this approach often helps people feel better, these individuals are prone to develop allergies to plants in the new location. What’s a better solution? Develop a well thought out treatment plan to manage your allergies and asthma year-round.

• Take antihistamines. These medicines often work well to control symptoms of allergic rhinitis (such as hay fever), regardless of what causes those symptoms. The drowsiness caused by products in the past is less of a problem with antihistamines now on the market. Anti-inflammatory nose sprays also can help and usually have few side effects. Similar medicines, specifically for the eyes, can reduce ocular symptoms. Antihistamines are available without a prescription (over-the-counter) as well as in forms which do not cause drowsiness and are somewhat stronger with a prescription from your physician.

• Nasal steroid sprays are more effective than antihistamines. They work best if started before or at the beginning of the season and if they are used everyday.

• Use quick relief or long acting medicines for asthma symptoms. Ragweed pollen also may trigger various symptoms of asthma, such as cough, wheezing, tightness in the chest or difficulty breathing. Your physician can prescribe medicines that provide immediate relief as well as for long-term control.

• Consider getting allergy shots. Also known as immunotherapy, this form of treatment can reduce your allergic response to specific allergens. In order for allergy shots to work, the allergens must be carefully identified with allergy testing. Allergy shots generally are taken over the course of several years, and it can take several months, or even one to two years, to see the full benefit. With proper materials and dosage, you may see major improvements in your symptoms.

Who should treat ragweed allergy?

Many patients are treated successfully for allergies or related asthma by their pediatrician, internist, or family physician. However, if your allergy or asthma symptoms are not under control within 3-6 months, or if you have severe persistent allergy or asthma symptoms, or asthma or allergy episodes that need emergency treatment, it may be time to see a specialist. Allergists/Immunologists or pulmonologists (who specialize in the treatment of lung diseases) are specialists who treat allergies and asthma. Practitioners who have completed training in those specialties are usually called board-certified or board- eligible.

Does health insurance cover treatment for ragweed allergy?

Most health insurance plans provide some level of coverage for allergy or asthma patients. Check with your insurance carrier for details. Some things you may want to find out might include:

• Do you need a referral to an allergy care specialist from your internist, family physician, or pediatrician?

• Does the insurance carrier offer any patient education or specialized services related to allergies, nasal allergy in general or asthma?

• What coverage is offered for pre-existing conditions?

• What medicines are not covered by your plan? (There can sometimes be a delay in approving newly released medicines. Your physician may know about them, but your insurance may not cover them yet.)

• Are allergy shots (immunotherapy) covered under your plan?

The information provided in this fact sheet should not be a substitute for seeking responsible, professional medical care.

Reprinted with permission from “Asthma and Allergy Answers,” the patient education library developed by the Asthma and Allergy Foundation of America.

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